Add json viewer and update content layout

[Kaveh-ap]

Summary

Add a BodyViewer component for displaying request/response bodies with JSON tree viewing and text fallback, plus initial expansion controls throughout RequestDetails. Also fix Header rendering to avoid array children in Text.

Motivation

• Improve readability of large JSON payloads with a collapsible tree.
• Provide better defaults via initial expansion controls for sections (headers and bodies).

Changes

• New component: BodyViewer
  • Detects JSON strings and renders a collapsible tree; falls back to text view.
  • iOS uses read-only TextInput for large content rendering reliability.
  • Supports data prop to bypass parsing and render prepared JSON.
  • Basic styling and nested scroll support for better UX.
• RequestDetails enhancements
  • New props:
    • initialRequestHeadersExpanded?: boolean (default: true)
    • initialResponseHeadersExpanded?: boolean (default: true)
    • initialRequestBodyExpanded?: boolean (default: true)
    • initialResponseBodyExpanded?: boolean (default: true)
  • Uses BodyViewer for request/response bodies with collapsible sections.
  • Adds “Share full request” and “Share as cURL” actions.
• Header fix
  • Concatenate the collapsible indicator and title into a single string to avoid array children in Text.
  • Indicator ▼/▶ shows only when collapsible.

Usage

<RequestDetails
  request={request}
  onClose={close}
  initialRequestHeadersExpanded={true}
  initialResponseHeadersExpanded={false}
  initialRequestBodyExpanded={true}
  initialResponseBodyExpanded={false}
/>

If you want to directly render JSON data:

<BodyViewer data={{ foo: 'bar', list: [1, 2, 3] }} initiallyExpanded />

UI/UX

• JSON bodies: Collapsible, indented view with alternating backgrounds per level.
• Text bodies: Scrollable view; on iOS uses read-only TextInput for large content stability.

Backward Compatibility

• Defaults keep previous behavior (all sections expanded initially).
• No breaking API changes.

Testing

• All tests pass.
• Header tests fixed by ensuring Text receives a single string.
• Manual checks for:
  • Collapsible behavior for headers and bodies.
  • JSON parse vs. plain text fallback.
  • Share actions.

Performance

• JSON parsing only when content is a string and data isn’t provided.
• Tree rendering uses toggling to limit on-screen content.

Screenshots/GIFs

[seyedmostafahasani]

@alexbrazier
Would you please check this PR?
I think it is very useful.

@Kaveh-ap
Thanks for creating this PR.